The present invention relates to bearings in general, and more particularly to bearings to be used for mounting a blade-supporting shaft on the bottom wall of a mixing container of a household mixer.
There are already known various constructions of mounting arrangements of this type, among them such which utilize a friction bearing which is accommodated in a sleeve-shaped carrier body or portion rigid with the bottom wall of the mixing container and bounding a passage which communicates the interior of the mixing container with the exterior thereof at the bottom wall.
It is well known that most friction bearings must be lubricated, usually by oil, so as to reduce the frictional resistance between the two mutually displaceable contact surfaces of the shaft, on the one hand, and of the friction bearing, on the other hand, to thereby avoid seizing of the shaft in the bearing and/or rapid deterioration of the bearing due to wear thereof. Thus, it has been already previously proposed to use oil-lubricated bearings in the above environment. However, experience has shown that the prior-art mounting arrangements utilizing lubricated friction bearings are prone to lose, within a shorter or a longer period of time, depending on the particular construction of the mounting arrangement, the supply of lubricating oil or, in other words, run dry. It will be appreciated that, when this happens, the now unlubricated bearing will deteriorate rather rapidly, requiring an expensive replacement thereof or even the purchase of a replacement mixing container or even of the entire mixer. This, of course, is very disadvantageous.
In one of the proposed constructions of the mounting arrangement of this type, which has been disclosed in the German published patent application DT-AS 1 008 058 two cylindrical friction bearings are arranged in a carrier body, each at one exial end thereof. Then, a lubricant-receiving space is obtained between the two friction bearings which are axially spaced from one another. A closable duct, which is filled with a lubricant, penetrates through the housing of the mounting arrangement and communicates with the lubricant-receiving space. As a result of this construction, it is possible to replenish the supply of the lubricant in the lubricant-receiving space through the above-mentioned channel and thus supply the lubricant to the two bearings to be lubricated. However, some of the lubricant will escape from the lubricant-receiving space past the bearings and out of the carrier body, the escaping amount of the lubricant being lost. Thus, this particular mounting arrangement is disadvantageous in two respects. First of all, it is a drawback of this arrangement that the proper amount of the lubricant within the carrier body can be maintained only by replenishing the supply of the lubricant in the lubricant-receiving space from time to time. On the other hand, it is also disadvantageous that the escaping lubricant can come into contact with the contents of the mixing container and contaminate the same if not render it useless altogether.